Windows Home Server Data Corruption Fix Coming in June

A Windows Home Server bug that's corrupting some users' data won't be fixed
until June, Microsoft announced this week.

The problem -- which occurs when "certain programs are used to edit or
transfer files that are stored on a Windows Home Server-based computer that
has more than one hard drive," according to Microsoft -- was first
acknowledged by Redmond late last year.

The Windows Home Server team announced the timeline for the patch on its blog Monday. "Thorough testing of the fix is critical and will take time," the post reads. "We have coded a part of the fix which is currently being tested internally...Once the patch has passed internal quality bars, external participants will be asked to help test the fix. Our current plan is to release beta test versions of a fix over the next few months, with a final version currently estimated for June 2008."

Microsoft said that a "very small number" of users have been "confirmed" to have encountered the bug. "Some of the instances that were initially attributed to this issue ended up being something else, such as a faulty network card/driver, old routers with outdated firmware, or people incorrectly testing the limits of their home servers," the post reads.

Microsoft has updated its Knowledge Base article about the problem, KB946676, with more details on the cause and some suggestions for working around it.

According to the KB article, the problem is caused by a clash between Microsoft's NTFS file system and Home Server's file system mini-filter drivers, used for storage. Data corruption can happen when the mini-filter driver redirects shared folders on multiple drives, causing sync problems between Memory Manager, NTFS and Cache Manager. (A detailed technical brief on the problem can be found in PDF format here.)

To avoid the bug, Microsoft suggests using read-only settings for Shared Folders,
not using Windows Media Player or other "media management" programs
to import files, and not using applications to open files stored on Shared Folders
"because some applications may change the metadata of a file without explicit
user action."